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1200GTO (for mounts - Astro

1. s he L kanne Satins i P al Ake Astronomers L y 4 KS GERMAN Eou WITH L 3 Sawa Meror ASTRO PHYSICS INC 11250 Forest Hills Road Machesney Park IL 61115 Telephone 815 282 1513 Fax 815 282 9847 support astro physics com www astro physics com June 1 2006 ASTRO PHYSICS 1200 GERMAN EQUATORIAL WITH GTO SERVO MOTOR DRIVE For Mounts shipped starting in May 2006 Beginning with Serial Number 1200572 MODEL 1200GTO PARTS LIST MODEL GTOCP3 FEATURES AND SPECIFICATIONS INTRODUCTION Why Polar Alignment is Important Compensation for the Earth s rotation ASSEMBLY DIAGRAM BEFORE YOU LEAVE HOME Gross Latitude Adjustment for 1200GTO German Equatorial Mounts Attach Pier Adapter to Pier Post purchased separately Standard Pier Adapter 1200SPA Precision Adjust Rotating Pier Adapter with Azimuth Bearing 1200RPA Hi Lo Latitude Wedge Pier Adapter Assembly for 0 22 or 69 90 Latitude North or South 12Z00WDGA Available late in 2006 AT YOUR OBSERVING SITE Assemble Pier purchased separately Assemble Polar Axis Assembly to Pier or Tripod Polar Alignment Part 1 Rough Alignment Altitude and Azimuth Adjustments Rough polar alignment Assemble Declination Axis Removing Declination Axis at the End of your Observing Session Attach Mounting Plate purchased separately Attach Counterweight Shaft and Counterweights Attach Mounting Rings and Scope purchased separately
2. of mix ups in the CCD software Maxim for instance the axes are identified backwards When you are trouble shooting remember RA is the only axis that must move at the sidereal rate and is the only axis that can trail a star if it is not moving correctly at that rate The DEC axis does not move after a slew and will not trail a star except by a very slow long period drift due to polar misalignment etc It will not trail a star image EVEN if it has 10 degrees of backlash so that analysis is definitely suspect I m having a frustrating guiding problem with my mount and need to figure out my next steps Your next step would be to remove the camera and place a high power eyepiece with crosshair reticle into the focuser Then sit down and watch what happens to the guide star With the eyepiece and reticle you can see whether or not the mount is tracking smoothly and how the periodic error is manifesting itself Yes you will have periodic error and any good CCD camera will pick it up to give you oval stars that is a given What you need to find out is whether this periodic error is within limits 3 5 arc seconds for the 900GTO and 2 5 arc seconds for the 1200GTO and whether it is smoothly varying You can also do some hand guiding using the 4 buttons on the keypad It will tell you how responsive the mount is to your guiding inputs and may even show some hidden problems when you try to keep the star on the crosshairs Alternately you can use
3. this mount will allow you to maximize your night out under the stars The advanced keypad features allow you to slew automatically to objects in a wide range of databases as well as any R A Dec coordinate A large selection of common names for stars and other objects makes your selection a snap The rapid slew rate of 5 degrees per second 1200x allows you to locate objects very quickly and accurately You will be very pleased with the intuitive operation of this keypad There are no complicated sequences of keystrokes to remember It is so easy to use that even if you don t use it for a few months you will feel at home with the keypad very quickly PulseGuide is a stand alone Windows 98 ME 2000 NT4 XP utility that provides complete remote control of all Astro Physics GTO mounts It derives its name from its most distinctive feature pulse guiding which can improve unguided tracking Specifically it can help correct tracking errors caused by polar misalignment and atmospheric refraction You can also train PulseGuide to track objects moving relative to the stars such as asteroids comets and the moon In addition to pulse guiding PulseGuide also has many useful utility features PulseGuide was written by Ray Gralak of Sirius Imaging Please refer to his website htto www pulseguide com for further developments and enhancements PEMPro Periodic Error Management Professional is a Windows software application that makes it ea
4. tightened evenly with the same tension i e all four half tight all four fully tight etc In order to feel the effect of the clutch knobs you may wish to partially assemble your mount Fit together the R A and Dec assemblies plus mounting plate and counterweight shaft Do not put scope and counterweights on at this stage With the above assembly with the clutch knobs firmly hand tightened as shipped you can feel the amount of force needed to move each axis by hand Grab each end of the telescope mounting plate and move it with a backward and forward movement of the Dec axis You will feel considerable resistance to this motion Perform the same operation on the R A axis by moving the counterweight shaft backward and forward With a well balanced telescope the above tightness of the clutch knobs will be sufficient for all normal conditions of use Now if you proceed to mount up and balance your telescope you can feel what this resistance in R A and Dec movement backwards and forwards is like when you make these motions from the eyepiece end of your telescope as you would during normal use when slewing pushing by hand to acquire an astronomical object within the field of view of your finder or scope How tight can the clutch be and can you do any damage by pushing against them The maximum tightness of this clutch system is 1 3 turn with a 5 32 hex key further in than the tension you can achieve with the knobs by hand You will
5. 0 5x Press the keypad North button until the guide star has moved approximately 6 pixels from the center Now press the South button in very short pulses and note which direction the star moves It should move back toward the middle after a few button presses It might move slightly up or down or it might continue to move further away from the middle or any combination Please note exactly how far and wees hee in which direction the guide star moves pixel d RE mF position is displayed in the guide box at right in Maxim Please allow a moment for the star to settle down after each button press Step 3 Press the South keypad button until the star has moved 6 pixels off the center in the REEN n Pay ST one rel arel anl Fasas ree em ec opposite direction Repeat Step 2 and note T Lama Deck du Lest exactly the motion of the guide star as you move it with the pulsed motion at 0 5x You may wish to enable Track Log to record R the numbers for further study Please note on the log what you did at what time so the results will be useful later Mi Kean 8 R You have now characterized the Dec axis fais ale HM ae e ka e L S SSS SS Fem 09 15 03 34 ASTRO PHYSICS MOUNTING PLATE FASTENER CHART 15 Flat 18 Flat 8 Dovetail 15 Dovetail Dovetail Plate Dovetail Plate 15 Ribbed 15 Ribbed 24 Ribbed Plate Plate Plate Plate for Losmandy D for Losmandy D Plate Plate Plate FP1500 FP1800 D
6. 1200GTO or do astrophotography you must polar align Procedures will be discussed here however you will complete this alignment when your scope and other equipment are mounted Methods for fine polar alignment e Polar Alignment Scope Our optional polar scope PASILL4 or earlier models will allow you to quickly align your mount on the pole stars The reticle was designed for use in both the Northern and Southern hemispheres Even users of the GTO computerized mounts will find these polar scopes useful particularly if your telescope is not orthogonal to the mount please refer to the keypad manual for a discussion of orthogonality If you have a polar alignment scope please read the instructions sheets that come with it If you are planning long exposure astrophotos or imaging we suggest that you use the polar axis telescope then tweak the final polar alignment by using the GTO keypad and perhaps CCDOPS from SBIG discussed below or other similar alignment program e GTO Keypad Please refer to the instruction manual for the GTO Keypad and read the section describing the startup Sequence and various polar alignment procedures including a procedure you can do in the daytime 15 e CCDOPS We suggest that you refer to detailed instructions in the GTO Keypad manual for a method that utilizes CCDOPS from Santa Barbara Instrument Group SBIG for precise polar alignment There are also other similar alignment procedures including one in M
7. PEMPYroAP or the full version of PEMPro to characterize your periodic error It will tell you things like the peak value and the smoothness of the error You can also characterize your mount tracking and guiding abilities using the Characterizing the Dec Motions test outlined in the Technical Support section of our AP website and included in the back of this manual Many times a problem guiding in RA can be the result of a Dec axis mechanical problem Not knowing this you will be forever chasing down the problem on the RA axis and never reaching a solution Characterizing your Dec Axis will at least show you that the mount reacts properly to the 4 guide directions If it shows a problem area then at least we will Know how to fix it Once you know that the mount is tracking in a normal fashion with normal periodic error profile you can go from there to begin setting up your guiding parameters It is not a piece of cake to get a guider like the ST4 to work flawlessly It is an art but once you know that the mount responds properly to the guide inputs it should be possible to set it up to work accurately If any problems occur please don t hesitate to contact Astro Physics for assistance ASTRO PHYSICS INC 11250 Forest Hills Road Machesney Park IL 61115 Telephone 815 282 1513 Fax 815 282 9847 support astro physics com www astro physics com 29 RECOMMENDED READING FROM OUR STAFF The Backyard Astronomer s Guide Terence Dicki
8. Physics pier Simply fit the Precision Adjust Rotating Pier Adapter into your Astro Physics Portable Pier just like the Standard Pier Adapter and fasten it from the side with the six screws and washers provided Again make sure that the Azimuth Adjuster Block is on the north side Attach to a flat surface on your own pier The Precision Adjust Rotating Pier Adapter must fit inside another part and be bolted from the side It cannot be bolted through the top as you can with the Standard Pier Adapter We recommend our 1200 Flat Surface Adapter 1200FSA The Flat Surface Adapter bolts onto the flat plate on top of your pier or tripod then the Precision Adjust Rotating Pier Adapter slips in just as it fits into our pier and you fasten from the side with the six screws and washers provided with the Precision Adjust Rotating Pier Adapter The bolt circle for attaching the 1200 Flat Surface Adapter to your pier is 9 230 diameter Using an ATS pier f you plan to use an ATS pier the O D of the plate will need to be modified by ATS for an additional charge The two recessed screws 3 16 hex shown by the arrows adjust the tension between the two plates of the Precision Adjust Rotating Pier Adapter These are preset to an optimal tension and should rarely if ever need to be re adjusted You do not need to tighten or loosen these two screws as part of your normal polar alignment routine Hi Lo Latitude Wedge Pier Adapter Assembly for 0 22
9. Pier West of True North Adjusted East Pier East of True North Adjusted West Altitude latitude adjustments Loosen the altitude locking knobs Move the polar axis up or down with the large altitude adjustment knob located in the front of the polar axis assembly The tommy bar can be positioned in any of the threaded holes located in the altitude adjustment knob Use this bar to help you turn the knob We have found that using the turnbuckle on the north leg of our pier also can make fine altitude adjustments if used One turn of the altitude knob is approximately 0 5 degrees 30 arc minutes Continue your azimuth and altitude adjustments until you can sight Polaris in the polar alignment sight hole At this point you have achieved a rough polar alignment which may be sufficient for casual visual observations if you are not planning to slew to target objects with the keypad When the R A motor is engaged the power is plugged in it will compensate for the rotation of the earth and keep the target object within the eyepiece field of view Your target object will slowly drift since polar alignment at this stage is only approximate However you can make corrections with the N S E W buttons of your keypad controller Tighten the altitude locking knobs by hand If you are using the Standard Pier Adapter or the Hi Lo Latitude Wedge tighten the pier knobs firmly by hand On the Precision Adjust Rotating Pier Adapter the knobs will alre
10. Screw _ Screw 4 10 32x34 4 10 32x3 As Socket Head Socket Head Nor Cap Screw Cap Screw Nor Accessory APPLICABLE P APPLICABLE Plate Ban 4mm Hex Key 5 32 Hex Key Flat Socket Cap Screw This page was last modified June 29 2005 Astro Physics Inc Socket Head Cap Screw Ban 11250 Forest Hills Road Machesney Park IL 61115 U S A Phone 815 282 1513 Fax 815 282 9847 35
11. With your l l hand push the polar axis upwards so a ee sa that the altitude locking knobs are 2 on each side positioned at the top of the altitude slot a this is the maximum altitude position Azimuth Adjuster Knob Some resistance will be felt with this operation as you are pushing against the weight of the polar housing and the resistance of the remaining polar axis pivot screw which has not been loosened 4 Before attempting to remove or move the altitude adjuster bar you must tighten the altitude locking knob on the motor gearbox housing side A is the This will prevent any downward movement of the polar axis during Latitude positioning of the altitude adjuster bar 5 While supporting the altitude adjuster bar remove the two screws that support it on each side 4 screws in all Keep the two ends of the bar in contact with the side of the mount don t remove the bar completely this tip is for your convenience 6 Determine the latitude range that you need and position the altitude adjuster bar so that the hole that is marked A as shown in the diagram is located at the appropriate hole position numbered 1 4 in the diagrams above and next page Note that hole A is located at the rounded part in the center of the altitude bar Hole A is the latitude hole 7 Attach two of the screws one on either side of the adjuster bar through the appropriate altitude adjustment position hole and int
12. base of the polar axis assembly so that the threaded holes of the pier top can be seen through each of the four slots Thread the four hand knobs loosely in place you will tighten these later after polar alignment with the washers underneath If you are using the Standard Pier Adapter be sure that the side with the rounded edge is facing down This will ensure smooth movements as you adjust your polar alignment The position of the washers does not Allow space for Azimuth Adjuster Block matter for the Precision Adjust Rotating Pier Adapter 11 Polar Alignment Part 1 Rough Alignment We recommend that you accomplish your polar alignment in two phases rough alignment and fine alignment Altitude and Azimuth Adjustments Rough polar alignment For rough polar alignment your goal is to sight the celestial pole when looking through the polar alignment sight hole in the center of the polar axis You will need to make altitude up down and azimuth side to side adjustments to the position of the mount We recommend that you do your rough polar alignment with the R A axis only since you will be making major adjustments to the position of the mount at this time The remainder of the mount telescope and counterweights will add considerable weight and require more hand effort Later you will do your final polar alignment with the telescope and counterweights attached but the adjustments will be small 1 If the Polar Sco
13. counterweights on the mount can decrease this unbalance threshold 2 The voltage of your battery has probably gone below 10 5 volts 3 The current rating of your AC DC power supply is too low Additional explanation During slewing the two motors draw up to 3 amps from a 12 volt source This may increase when the temperature approaches freezing or below It is recommended that your supply be rated at 5 amps 12 volts DC minimum 18 volts max If you also power other equipment CCD cameras dew heaters etc from the same source you will need a supply capable of up to 10 amps The more equipment you have the more current capability you will need For portable applications we recommend a heavy duty marine battery designed for deep discharge applications The most common problems are due to inadequate power supply The keypad reset or locked up when I plugged my CCD camera PC or other equipment into the same battery as the GTO mount was using The battery has a meter which shows 12V The meter is reading an average and will not show dips Gel cells have internal resistance which will cause voltage drop when the load changes When you connect an additional CCD camera and PC the load will drop below 9 volts and the keypad will reset or it may affect the GTO circuit itself and cause the keypad to lock up We recommend that you use a large marine battery that is not a gel cell and hook everything up to it before calibrating the GTO Or better
14. or 69 90 Latitude North or South 1200WDGA Available late in 2006 If your latitude is between 22 north and 22 south or above 69 either north or south this wedge assembly includes everything you need to place your 1200 mount in the proper position This adapter includes the machined wedge and flat plate the 1 2 Azimuth Adjuster Block four Pier Adapter Knobs with 5 16 ID x 1 OD flat washers the center pivot screw six 5 16 18 x 5 8 socket button head screws and six 5 16 x 9 16 OD x 0 060 flat washers which enable you to attach the pier adapter to your Astro Physics pier Please Note 1 The photo below is of the 900WDGA At press time we did not yet have a photo of the 1200WDGA The 1200WDGA will look very similar 2 The photo shows the Hi Lo Latitude Wedge ready to be used at tropical latitudes with the Azimuth Adjuster Block on the low side For extreme polar latitudes the plate on top of the wedge can be turned around to extend the useful range of your 1200GTO above 69 latitude Simply remove the two side knobs and then remove the six screws that attach the flat plate to the wedge Rotate the flat plate 180 and re assemble with the Azimuth Adjuster Block on the high side Attach to an Astro Physics pier To attach the Hi Lo Latitude Wedge to your Astro Physics pier simply set the adapter into the top of the pier post make sure the azimuth adjuster block is on the north side and fasten from the side with
15. package e A special screwdriver that has been modified by Astro Physics if you ordered it This screwdriver is marked with masking tape DO NOT REMOVE this tape Instructions for making your own tool can be found below and in the Technical Support section of our website e Replacement clutch plugs M12665 A What you will need e to 1 pound hammer e Aight machine oil example 3 in 1 Replacement of old Clutch Plugs Removal of the old plugs will be done by hammering the special screwdriver into the old plug This will create a driving slot for the screwdriver blade Please follow the steps below Remove the clutch knob from the clutch plug hole Insert the screwdriver into the clutch plug hole and press down firmly make sure the guide point on the screwdriver is fully engaged in the center hole of the old clutch plug Sharply hammer the screwdriver so as to drive its blade about 3 16 of an inch into the old plug The masking tape on the screwdriver shank will provide a good reference for this 3 16 depth The tape will be level with the top of the clutch plug hole when the correct depth has been achieved see the illustration below Solid Line hidden Clutch Plug Masking tape level with top of hole at correct 3 16 depth Maintaining a positive downward pressure turn the screwdriver in a counter clockwise direction This will cause the old clutch plug to unscrewed fr
16. see that each clutch knob has a 5 32 hex socket for tightening with an hex key With this extra 1 3 turn on each clutch knob the axis axes will be considered completely locked up and you should not attempt to push your scope by hand against this locked up resistance or undue stress will be placed on the worm wheel worm and bearings However if you are undertaking a very long astrophoto exposure it is advisable to increase the pressure on each clutch knob with the 5 32 key by about 1 8 turn past hand tight on Dec and 1 8th turn past hand tight on R A You may safely slew the scope by hand with this tension however you will notice considerably more effort is required to achieve movement This is the absolute maximum tension that can be used for hand slewing As a general rule if you have a big scope 7 or 8 refractor with all the accessories you will need more clutch tension than a 5 or 6 scope WARNING Resist the urge to over tighten the clutch knobs with the hex wrench This will only cause them to deform and lock into position If you find that you are no longer able to adjust the tension and the knobs are locked firmly in place so that the axis will not move please refer to the Clutch Plug Replacement Section at the end of this manual Balancing Your Telescope For proper operation the telescope must be adequately balanced along both axes Start by balancing the tube assembly First Balance the Declination Axis 1 Pos
17. the center This allows you to position the plate either forward or backward depending on the balance point of your telescope Attach this plate with six 1 4 20 x 1 socket head cap screws 15 ASTRO PHYSICS DOVETAIL DOVE15 FOR 15 SLIDING BAR SB1500 The 15 version of our dovetail plate is suited for the 130 f8 StarFire EDT 155 f7 StarFire EDFS ARO Maksutovs Takahashi scopes and other instruments of similar size The knob assembly features a brass pin with a tapered end to hold your sliding bar firmly without marring the aluminum Use with the 15 Sliding Bar SB1500 which is sold separately NOT for use with Losmandy D plates Also makes a great accessory plate when used with either the 1200RP15 or FP1800 with rings mounted to inside holes Attach with four 1 4 20 x 5 8 flat head socket cap screws 14 Attach Counterweight Shaft and Counterweights IMPORTANT e Always attach the counterweights before mounting the telescope to the cradle plate to prevent sudden movement of an unbalanced tube assembly which may cause damage or injury e Remember counterweights are heavy and will hurt if they fall on your foot 1 Thread counterweight shaft onto the Dec axis Be careful not to cross thread 2 Remove the safety stop a hand knob and washer were provided on older mounts from the end of the counterweight shaft Add sufficient counterweights 10 or 18 lb counterweights are available to the shaft to balance the teles
18. the improved azimuth adjuster assembly on all 1200GTO mounts produced after January 2004 and all upgraded older mounts If you have a permanent installation this base is a good choice since you will not have to set up every session The adapter includes the machined flat plate four machined aluminum lock knobs with 5 16 ID x 1 5 OD stainless washers the azimuth adjuster block center pivot screw and six 5 16 18 x 5 8 button head screws and washers All machined parts are black anodized The Standard Pier Adapter was designed to fit into a 10 x 0 094 wall tube Attach to an Astro Physics pier To attach the pier adapter to your Astro Physics pier simply lt gt aaa a set the adapter into the top of the pier post make sure the azimuth adjuster block is on the va Q o Kod north side and fasten from the side with the six screws and washers provided E d Attach to a flat surface on your own pier f you are mounting to a flat surface of your N Coy lt own design simply use four 1 4 20 stainless steel cap screws of appropriate length fastened through the top of your adapter Refer to the diagram in the back of the manual ae for bolt pattern information i ae If you prefer a more finished look you may wish to consider using our 1200 Flat Surface Adapter 1200FSA The Flat Surface Adapter bolts onto the flat plate on top of your pier or tripod then the Standard Pier Adapter slips in just as it fits into our pier and yo
19. the six screws and washers provided Attach to a flat surface on your own pier The Hi Lo Latitude Wedge must fit inside another part and be bolted from the side It cannot be bolted through the top as you can with the Standard Pier Adapter For custom installations we recommend our 1200 Flat Surface Adapter 1200FSA The Flat Surface Adapter bolts onto the flat plate on top of your pier or tripod then the Hi Lo Latitude Wedge Pier Adapter slips in just as it fits into our pier and you fasten from the side with the six screws and washers provided The bolt circle for attaching the 1200 Flat Surface Adapter to your pier is 9 230 diameter 900WDGA Using an ATS pier The O D of the plate will need to be modified by ATS for an Wedge Pier Adapter Assembly additional charge 10 AT YOUR OBSERVING SITE ao Adapter Assemble Pier purchased separately i Begin by assembling the portable pier at the desired observing A S location Take note which direction is north 1 Rods with Slide the three legs onto the nubs of the base and rotate the assembly so that one of the legs points toward north or south if that is your preference Place the pier post on the base orienting the center azimuth block directly north If you choose to have one leg north then the pier adapter plate will have to be installed with the azimuth block directly over a turnbuckle If you have one leg south the pier adapter plate will have to be ins
20. worm shaft it will turn slowly at the sidereal rate without imparting this motion to the worm itself because it is slipping At some point the set screw will catch on the edge of the flat on the worm shaft and begin to drive the worm gear So this looks like classical backlash when in fact it is not backlash at all and all attempts at setting the gear mesh on the worm are futile to correct this lost motion When we get a chance we will post a complete set of pictures on our web site showing how to check for this loose gear condition Meanwhile you can take the cover off the motor gearbox and acquaint yourself with the spur gears inside Do not be afraid to move and wiggle things by hand to see how stuff works One more thing sometimes a person will be absolutely certain that it is the Dec axis that is giving him a problem because the CCD program he is using shows some improper function in the Y axis and he is absolutely certain that Y Dec After much sending of equipment back and forth to our facility it finally is determined that it was the other axis after all that had the 28 problem PLEASE please make sure that you have identified the proper axis In the case of any kind of motion problem like this it would be really helpful if you removed your camera inserted an eyepiece with crosshairs and actually looked to see what was happening You can then identify exactly which direction RA or DEC is moving after a slew Sometimes because
21. yet put the other equipment on a separate battery What is the maximum voltage that can use to power the servo drive The servo drive of the 900GTO and 1200GTO will withstand up to 24 volts without any sort of damage to the internal electronics according to our engineer However above about 17 volts the motors may become a bit jittery because of the higher gain with this much voltage The system works very well with 15 16 volts For polar alignment am using declination drift technique with stars on east amp south Now I do not see any drifts in declination on both sites E amp S so the mount should be properly aligned However I have still small drift in RA which looks like the RA motor is a bit faster than earth rotation This drift is something like 1 5 arcsec during 1 minute or so and is accumulated over time so it doesn t look like periodic error The sidereal tracking rate is exact in the mount it is crystal controlled and checked here for accuracy However the stars do not move at exactly the sidereal rate everywhere in the sky The only place they move at that rate is straight overhead As soon as you depart from that point in the sky the stars will be moving more slowly especially as you approach the horizons 2 Thus it looks like the mount is moving slightly faster than the sidereal rate Just because you have done a classic drift alignment does not mean that the stars will now be moving at the sidereal rate everywh
22. AXIM DL from Diffraction Limited e Star Drift method Traditionally this has been regarded as the most accurate method of polar alignment However if you are using the old method of drift alignment star near eastern horizon etc you are doomed to failure To obtain more accurate results choose stars somewhere near the celestial equator due south or slightly east and west but not below 45 degrees elevation If you attempt to drift align below that you will encounter atmospheric refraction which skews your alignment e Members of the ap gto Yahoo group occasionally discuss alternative methods of polar alignment that they have found helpful We suggest that you participate in this Internet discussion group Follow the links from the sidebar of our website to find the group Azimuth Adjustments The one piece Azimuth Adjustment assembly makes for easy and accurate polar alignment in your observatory or in the field The heavy duty construction and integrated one piece design results in smooth control of the azimuth axis Large left and right adjuster knobs are graduated for precise control of azimuth position angle The small graduations are 1 06 arc minutes per graduation long graduations are 5 3 arc minutes per graduation one full turn is 31 8 arc minutes or 53 deg The size of the knobs makes them easy to turn with very little torque required even with the mount fully loaded The procedure for making azimuth adjustments is somewhat diff
23. ITH GTO SERVO MOTOR DRIVE For Mounts shipped starting in May 2006 Beginning with Serial Number 1200572 MODEL 1200GTO PARTS LIST MODEL GTOCP3 MD k SS Ss k k ss st k Polar axis assembly right ascension R A with Servo Box GTOCP3 Declination Dec axis assembly 18 5 Stainless counterweight shaft 1 875 dia with machined black anodized safety stop Y cable R A portion is 12 5 long and Dec portion is 37 5 long D C power cord cigarette lighter adapter on one end 8 long GTO Keypad controller with 15 coiled cable Keypad Protector KEYPRO Hex key set 8 32 thumbscrews substitute these for 8 32 set screws that hold GTO Servo Control Box in place if you wish PEMProAP Periodic Error Management software for Astro Physics mounts CD ROM PulseGuide by Sirius Imaging remote control utility for improved guiding CD ROM In order to fully assemble your mount you will need the following items sold separately e Telescope mounting plate many choices to fit your telescope and observing needs e 22 to 69 latitude choose either the Standard Pier Adapter 1200SPA or the Precision Adjust Rotating Pier Adapter with Azimuth Bearing 1200RPA Either adapter will come with six 5 16 18 X 5 8 button head screws for attachment to the pier four pier knobs for attaching the mount to the adapter and the azimuth block for use with the Heavy Duty Azimuth Adjuster found on all 1200GTO moun
24. OVE08 DOVE15 Series Plate Series Plate 9QO0ORP 1200RP15 1200RP DOVELM2 DOVELM16 Not pee 4 Y 20x1 2 4 4 20x1 2 4 14 20x5 8 Recommended Beek Head Socket Head Flat Socket Socket Head 4 4 20x7 8 G GAR R Screw Cap Screw Cap Screw Socket Head Cap ounts Screw IN 1 w p Ru Ww MM Jm NoT NoT APPLICABLE S Renes Not APPLICABLE 4 M6 1 0 4 OS as Flat Bus Flat K aes ree Pes ocket Head Cap 1 0x 25mm 600E Socket Head oad ara a a Screw Socket Head Cap Mounts Cap Screw NII Screw SN T 7 Ban pun NNN IW a 20x5 8 Flat Nor Nor Shee APPLICABLE APPLICABLE 4 20x5 8 Cap Screw Socket Head 2 Y 4 20x1 rag Screw Socket Head Cap ee gs Screw 4 Ye lal 20x1 4 4 20x5 8 1 20x3 4 6 Y 20x1 20x5 8 Flat Socket S Socket Socket Head Flat Socket 900 Socket Head Can Screw Cap Screw R Screw Cap Screw Mounts ap Screw LD Yar a ae l ne Socket Baw 4 Y 20x1 WAAL l Cap Screw Socket Head Cap Use Q4047 R l _ Screw Adapter 1 4 ane 4 r ThE Socket Head WANK Cap Screw 2 Y 20x5 8 Flat 2 4 20x1 Socket Flat Socket Cap Screw Cap Screw 4 4 20x34 6 4 20x1 4 4 20x5 8 6 4 20x1 6 20x1 Socket Head Flat Socket Flat Socket A Socket Head Socket Head 1200 Cap Screw Cap Screw Nor Cap Screw Nor Cap Screw Cap Screw Mounts APPLICABLE E and or and or APPLICABLE 4 4 20x9A 4 Va 20x1 Socket Head Socket Head Cap Cap
25. Please refer to the illustration on p 12 Do not leave the knob you have backed off loose It must be gently snugged against the azimuth adjuster block to hold the azimuth angle you have set Follow one of the alignment methods discussed above in the Polar Alignment section Once your azimuth position has been attained do not tighten the hand knobs any further since this is likely to disturb your alignment Standard Pier Adapter 1200SPA and Hi Lo Latitude Wedge 1200WDGA Each of the azimuth lockdown knobs has a hardened washer With these washers the lockdown knobs can hold the mount down tight while still allowing the axis to be easily adjusted with your fingers These will eliminate minor shifts in the axis when you are tweaking your azimuth adjustment The washers have a sharp edged side and a rounded edge side the difference is subtle Place them with the sharp edge of the washers facing up toward the knob rounded edge down onto the painted surface of the base plate If you install the washers with the sharp edge down they will bind into the paint and prevent smooth movement If you do not have a permanent installation you may wish to mark the down side of the washer with a permanent marker so that you can quickly identify the desired orientation 1 The altitude axis should be fully locked down with a hex key before adjusting the azimuth 2 Follow one of the methods of polar alignment mentioned above 16 3 During the in
26. Polar Alignment Part 2 Fine Polar Alignment Methods for fine polar alignment Azimuth Adjustments Precision Adjust Rotating Pier Adapter with Azimuth Bearing 1200RPA Standard Pier Adapter 1200SPA and Hi Lo Latitude Wedge 1200WDGA Altitude Adjustment Tips for Adjusting the Altitude Understanding the R A and Dec Clutch Knobs Balancing Your Telescope First Balance the Declination Axis Second Balance the Polar Axis ooo NN ODO aa on A O SERVO MOTOR DRIVE GTO Control Box Model GTOCP3 R A and Dec Cable Connections 12V Connector POWER Indicator Light KEYPAD Connector RS 232 Connectors FOCUS Connector RETICLE Connector AUTOGUIDER Connector 6V Connector N and S Switch Drainage Holes Removing the GTO Control Box From 1200 Mount GTO KEYPAD OPERATION PULSEGUIDE BY SIRIUS IMAGING PEMPROAP BY SIRIUS IMAGING CABLE MANAGEMENT 1200 Motor Cables Accessory Cables Example from International Space Station Amateur Telescope ISS AT Project SLEWING YOUR MOUNT IN BELOW FREEZING TEMPERATURES MOUNT CARE CLEANING AND MAINTENANCE Care Cleaning and Touch up Routine Mount Maintenance ADDITIONAL TIPS AND SUPPORT TROUBLESHOOTING RECOMMENDED READING FROM OUR STAFF STANDARD PIER ADAPTER OF THE 1200 MOUNT CLUTCH PLUG REPLACEMENT FOR 900 OR 1200 MOUNT Construct Your Own Clutch Plug Extraction Tool CHARACTERIZING THE DEC AXIS MOTIONS ASTRO PHYSICS MOUNTING PLATE FASTENER CHART ASTRO PHYSICS 1200 GERMAN EQUATORIAL W
27. To system that slews at high speeds The wear on the worm and wheel teeth is extremely high and can develop very high periodic error after a short time due to scratches and high spots that develop on the gear teeth At this time we have no solution to ultra low temperatures Last night it was 8 F here and tested several of our mounts in the observatory Two are very old from the original batch and one is brand new All worked well at 600x but showed signs of laboring at 1200x slewing use a 12 volt marine battery to power them replaced the marine battery with a variable power supply that varied from 12 volts to 18 volts At 12 volts when both motors were slewing at 1200x the power draw was in excess of 8 amps in summer this is around 2 5 amps The motors were laboring and not running smoothly at full speed turned up the voltage to 15 volts and the current draw dropped to around 5 6 amps The motors worked smoothly at 1200x with no hesitation at that voltage level would recommend for cold weather work to get a supply that can deliver 15 16 volts at a rated current capacity of 10 amps Higher than that is not necessary Above 18 volts is not recommended 25 MOUNT CARE CLEANING AND MAINTENANCE Like any fine piece of equipment your mount s longevity and performance are directly correlated with the quality of the care that you give it Handle it with respect keep it as clean and dry as is practical and perform a few minor mai
28. We suggest that you install the rings on the mounting plate then open the rings lift the scope in place close the rings and tightened the knobs To balance the scope you can loosen the knobs enough to slide the scope forward or backward as needed Another approach is to attach the rings to the scope beforehand then lift onto the mounting plate However the rings must be spaced exactly the correct distance apart to match the holes in the plate This maneuver may be particularly difficult to accomplish with a large heavy instrument Dovetail plates or sliding bars Attach mounting rings to the male dovetail plate sliding bar matching the appropriate threaded holes on the bottom of the mounting ring Again you have the option of attaching this dovetail ring assembly to the mount and then lifting your scope in or placing the scope in the rings then lifting the entire assembly to the female mounting plate already attached to the mount Dovetail plate sliding bar combinations are quick versatile and convenient hence their popularity Simply loosen the knobs and tilt the sliding bar into place in the dovetail receiver Once in place tighten the knobs to lock everything securely Loosen the knobs and slide the scope rings sliding bar assembly in the dovetail channel as needed to balance the system and then re tighten when balanced Polar Alignment Part 2 Fine Polar Alignment If you plan to use any of the go to functions of the
29. ables emerge to the GTO Control Panel Attach the short part of the Y cable to the R A motor housing and the long part of the cable to the Dec motor housing Lock all connectors Refer to the section below for further information about positioning the cables 12V Connector Place the DC power cord included with your mount into the phono plug outlet marked 12V on the GTO Control Panel and lock in place Plug the cigarette lighter plug end of the cord into your power source The acceptable voltage range is 11 5 to 16 Above 18V is not recommended Suggested power sources include portable rechargeable battery pack auto or marine battery or power supply filtered and regulated for 110 volts with a minimum output of 5 amps at 12V DC There is no on off switch We recommend that you plug the power cable into the servo box after the keypad controller To turn the unit off simply disconnect the power cable Considerations for observatory installations We suggest that you disconnect your GTO Control Box from 110V and any other device CCD camera computer etc when you are not using your mount so that if your observatory experiences a power surge or lightening strike your mount electronics will not be damaged If you operate your mount remotely you will have to leave your power cable connected just as you do for the rest of your electronic equipment You may want to consider 20 surge protectors or other protective measures to protect from vo
30. ady be tight 12 Assemble Declination Axis 1 Do not have your telescope or counterweights connected to the Dec axis assembly for either assembly or disassembly of the Dec and RA axes R A Axis Dovetail A m 2 Position the R A axis as shown in the illustration at right with the single pocket A at the top opposite the altitude adjuster knob Firmly tighten R A clutch knobs a yE gt 3 During shipment the Dec axis assembly lock knobs will be fully screwed into the Dec axis For correct assembly these lock knobs should be unscrewed at least 7 full turns and no more then 8 5 full turns This is between 5 16 and 3 8 out from the shipped tightened position Note These lock knobs can be completely removed from the Dec axis assembly with about Single Pocket 9 5 full turns out Dovetails 4 Position the Dec axis above the R A axis as Parallel Guides shown in the lower illustration at right a light Altitude Adjuster movement wiggle in the downward direction Knob arrow A will help to correctly seat the principle Clutch Knobs dovetail s and parallel guides 5 When both Dec and R A assemblies are fully seated hand tighten both Dec lock knobs 6 Thread the counterweight shaft into the Dec axis 7 Remove the Safety Stop from the base of the counterweight shaft Add sufficient counterweights 10 or 18 lb counterweights are purchased separately to the declination shaft to ba
31. ar axis assembly Many users find a polar axis telescope useful for zeroing in on the pole quickly particularly with telescopes that are not orthogonal to the mount e Extension cable for keypad Please call Astro Physics to obtain a quote on the length of extension cable you need Note on Encoders Mounted encoders can no longer be used with the 1200GTO for mounts shipped starting in May 2006 beginning serial number 1200572 because of the counterweight shaft re design They are not needed since the go to functions of the mount are so much more accurate The encoder that is built into the servo motor itself has a resolution of 0 05 arc seconds vs 324 arc seconds for mounted encoders 3 R A worm wheel Dec worm wheel Worm gear R A shaft R A thrust bearings Dec shaft Dec thrust bearings Counterweight shaft Latitude range Azimuth adjustment Setting circles Right ascension Declination Motors Power Consumption Power requirements Weight of mount Capacity of mount FEATURES AND SPECIFICATIONS 10 3 225 tooth aluminum 7 2 225 tooth aluminum Brass 3 35 diameter 9 5 diameter 2 36 diameter 6 5 diameter 18 5 useable length 1 875 diameter stainless steel removable 22 69 degrees with or without polar scope attached Approximately 14 degrees Porter Slip Ring design engraved 4 minute increments pointer 1 degree increments pointer Zero cogging
32. changes from red to yellow and the motors stop or go out completely for mounts shipped after 02 25 00 1 The motors are overloaded probably due to an unbalanced load on your mount Rebalance your telescope and then press one of the N S E W buttons to reset the keypad Re enter the last object on your keypad and the scope will slew to the correct position Even though your motors had stopped the logic in the control box retained the scope position in memory As long as you didn t change the pointing position of the scope you are still calibrated If the scope was moved during re balancing simply enter a nearby bright star on the hand controller press GOTO and allow the mount to finish slewing You can then move the scope manually or with the N S E W buttons to center the star in the eyepiece and press the 9 RECAL button This will recalibrate the mount Additional explanation The GTO drive circuit includes logic for overload protection to prevent burning out the expensive servomotors in case of severe overload on the two axes The primary cause is an unbalanced load in R A If the extra load opposes the motor rotation the motor must work harder to track at the sidereal rate and the current will rise to high levels If the current exceeds the trip point for more than a minute the logic will shut the motor off and tracking stops It typically takes about 4 Ib of unbalance to trip the overload but a very heavy load of scopes accessories and
33. cope you intend to use Loosen the counterweight knob and hold the counterweight with the knob pointing downward so that the brass pin will move from the center opening allowing the counterweight to slide into position Always use two hands to attach or move them on the shaft It is advisable to have the counterweight knob pointing down toward the pier This will minimize the chance of accidentally loosening the counterweight during the observing session 3 Re attach the safety stop to the end of the counterweight shaft This will help to prevent injury if someone accidentally loosens the counterweight knob A firm tightening of the counterweight knob will not damage the surface of the counterweight shaft The pin that tightens against the stainless counterweight shaft is constructed of brass Likewise the bronze sleeve that has been press fit into the center of the counterweight will prevent marring of the shaft as you move the counterweights Attach Mounting Rings and Scope purchased separately Flat and ribbed plates Our flat and ribbed plates are constructed with keyhole slots at the location where your mounting rings attach This feature enables you to partially loosen the screws on your rings just enough to insert them into the larger part of the keyhole then slide the rings to the narrow part and tighten them with a hex key We prefer this keyhole method to the standard way of completely removing the screws and dropping them in the grass
34. d more labored in cold weather As the temperature drops we recommend that you reduce your slewing speed to the slowest slew rate The cold causes the lubricants to get stiff in the gearboxes This can make the high speed gears resonate and sound screechy Lowering the slew speed in winter will eliminate this You might also want to add a drop or two of light machine oil to the center posts of the individual gears Just remove the cover on the gearbox and add the oil drops The noise is nothing to worry about Refer to the section of this manual entitled Slewing Your Mount in Below Freezing Temperatures The declination axis does not appear to be moving properly How can I check it Please refer to the appendix for the instruction sheet Characterizing the Dec Axis Motions which explains how to use Maxim DL software to characterize your mount s performance When I press the E button on my keypad it takes forever for the star to finally stop Adjusting the backlash control using the keypad helped but the problem is still there First the problem is most often caused by the worm and worm wheel not being in mesh this is often the case when a used mount is purchased and the previous owner never ever adjusted the worm mesh or the mesh was altered during shipment When the worm is out of mesh it takes the motor many seconds to reverse the tooth contact from leading to trailing edge because it is running at the very slow sidereal rate One could
35. ddle of the tube Loosen the R A clutch knobs Again be careful because if your scope is significantly un balanced it may swing rapidly in the out of balance direction Move the counterweight s up or down to achieve the correct balance in R A Again movement back and forth about the R A axis should have the same feel in both directions Re set the tightness of all 8 clutch knobs to the resistance you want making sure that each axis 4 clutch knobs are evenly tightened See section on clutch knobs above Try to anticipate any balance problems due to the extra weight of diagonals heavy eyepieces finders solar filters etc If the scope moves by itself when the clutches are loose then the scope is not balanced adequately You may want to tweak by carefully repeating steps 1 5 after everything has been attached to the telescope Be especially careful loosening the Dec clutch knobs NOTE A small amount of imbalance on the East side of the mount is permissible and even desirable for astrophotography and imaging Remember that if imaging several objects on different sides of the sky you may need to re adjust the balance to keep the east side slightly heavy 19 SERVO MOTOR DRIVE GTO Control Box Model GTOCP3 The GTO control box contains all of the circuitry to drive the two servo motors and the logic required to navigate the sky It will be operational and track at the sidereal rate when connected to both motors of th
36. e mount and a power source In order to control the movement of the mount you will need to connect at least one of these e GTO Keypad e PC computer with PulseGuide by Sirius Imaging The CD with this program is included with the mount The CD includes a complete user s manual in PDF format For the most updated version of the software check out the website www pulsequide com Please refer to the section later in this manual for further information regarding the capabilities of this program e Computer with astronomical software such as DigitalSky Voice or planetarium programs such as Software Bisque s TheSky Imaginova s Starry Night Nova Astronomics The Earth Centered Universe ECU version 3 1 or later and Chris Marriot s Sky Map Pro 6 or any ASCOM compatible telescope software all purchased separately The GTO Servo Control Box is mounted directly onto the polar axes of the 1200 mount Please remember that this box contains advanced electronics and must be treated with the same care given to other fine equipment You can see that the unit is machined of aluminum and is built to be rugged however it is not indestructible ASTRO PHYSICSINC f GTO CONTROL PANEL O g 6V MADE INTHE U S A AUTOGUIDER ki b ac 7 KC gt f m RETICLE ET S N MODEL GTOCP3 R A and Dec Cable Connections A Y cable with 10 pin connectors is included with your mount Attach the connector from which the two c
37. ere in the sky In order to increase the area of sky from the zenith that will give you fairly good tracking you will need to offset the polar axis by a small amount The amount will depend on what your latitude is The other approach is to vary the tracking rate for different parts of the sky Ray Gralak s Pulse Guide will allow you to dial in an exact tracking rate for any part of the sky Initially the mount was working fine Then suddenly the mount stopped tracking altogether Chances are that the motor was turning properly and driving the worm gear but that your clutches might have been loose and therefore the scope was not following the motion of the worm gear The fact that the high slew rate did move the scope does not change this because Roland has seen this himself where the tracking rate did not overcome the slipping clutches but the slew rate did If you are unsure of the motion of the motor just remove the motor cover plate and look inside You will see the motor turning Sometimes when you have the clutches loosely engaged and the counterweights are somewhat out of balance being heavy in the east then the clutches might slip at the slow sidereal rate In any case just to set your mind at ease simply remove the motor cover next time something like this happens and look at the motor shaft If the motor is not turning you will have some kind of electrical problem If it is turning then it is mechanical The motors sound louder an
38. erent with the Precision Adjust Rotating Pier Adapter 1200RPA Standard Pier Adapter 1200SPA and Hi Lo Latitude Wedge Assembly 1200WDGA If you are using your own pier adapter or one provided with the Particle Wave Technologies Monolith Pier there may be additional considerations to achieve smooth accurate adjustments Precision Adjust Rotating Pier Adapter with Azimuth Bearing 1200RPA The Precision Adjust Rotating Pier Adapter consists of two plates that allow ultra smooth adjustments for critical polar alignment When using the Precision Adjust Rotating Pier Adapter tighten the pier knobs fully by hand It is not necessary to use awrench These will remain tight during and after the adjustment procedure Also please note that the altitude axis should be fully locked down with a hex key before adjusting the azimuth Notice the two setscrews on the side of the Precision Adjust Rotating Pier Adapter These setscrews are used to apply tension to the rotating plate You may on rare occasions need to adjust these setscrews to gain the proper feel during the adjustment process If you notice a slight amount of shift particularly with a larger scope tighten the screws If you find too much resistance the screws may need to be loosened slightly Azimuth adjustment is accomplished with the two fine azimuth adjustment knobs one on each side of the mount You must back off the opposing azimuth knob in order to move the other knob in that direction
39. for the next session is much quicker The photo on the left shows how the cables were arranged on the 1200GTO that was installed at a permanent observatory for the International Space Station Amateur Telescope ISS AT project of the Astronomical League This mount is operated remotely and cable management is essential The scope is a modified Celestron C 14 and the accessories included CCD camera color filter wheel remote focuser and Kendrick Dew Remover Note how the wire bundle is attached to the mounting plate before looping back to the pier Attaching the wires securely to the plate 23 prevents any kind of motion or disturbances to the camera during image acquisition and guiding The loop is made long enough to allow the scope to reach all portions of the sky with plenty to spare The people who installed system ran the scope all over and reported zero interference This photo shows the mount and scope with the wire loop containing all the cables from the CCD camera color filter wheel remote focuser and Kendrick Dew Remover If you look closely you will notice that the two clutch knobs were removed and replaced with special Allen head bolts This allowed the Dec cable to slide easily over the axis in all orientations and there was no snagging of the wire anywhere Please call Astro Physics if you would like to order these bolts Do not try to install normal Allen head bolts For a portable setup we keep the ties wraps in
40. g Dec Cable connector Dec Clutch knobs 4 Dec Setting circle Sight hole cover R A Clutch knobs 4 Declination axis housing R A Setting circle an Right ascension axis housing ee Control box Altitude locking knob Counterweight shaft P eS Counterweight E gt knob i s X N Tommy bar 9 Altitude adjustment knob Pier Adapter Knob with Washer 4 Safety Stop R A axis rear cover Polar axis pivot screw Altitude adjustment position holes Polar Fork Counterweight ase assembly optional a Azimuth adjustment knob E 1200 Standard Pier Adapter 1200SPA wll o o oN r optional e 1200 Precision Adjust Rotating Pier Adapter a with Azimuth Bearing 1200RPA a optional Azimuth adjustment Block 5 16 18 x 5 8 buttonhead screws 6 Zl 5 16 x 9 16 O D x 060 washer 6 1200 Hi Lo Latitude Wedge Assembly 1200WDGA Optional BEFORE YOU LEAVE HOME Since most of us must set up our instruments in the dark in the cold or while battling mosquitoes a bit of pre planning and organization is important There are few simple things that can be accomplished in the comfort of your home before heading outside Gross Latitude Adjustment for 1200GTO German Equatorial Mounts Mounts shipped starting in May 2006 Beginning with Serial Number 1200572 NOTE Older mounts will have slightly different latitude ranges The latitude ran
41. g on how many available USB connections you have One member of the Yahoo Astro Physics GTO User s Group even reported success using a single USB connection on his computer with a 4 port USB hub and USB serial RS232 converters For amore detailed discussion go to the Yahoo ap gto user s group access it through our website and type pcmcia into the search box FOCUS Connector Attach the 3 5mm phono plug connector of your JMI Motofocus or other electric focuser optional accessories here Refer to the section regarding focus adjustment in the GTO Keypad Manual for instructions on using the keypad controller to adjust focus Alternatively you can verbally control the focus using the Focus Mode of DigitalSky Voice software RETICLE Connector If you wish to use the illuminator cable for our Polar Alignment Scope PASILL4 or earlier models a plug in type guiding eyepiece with an illuminated reticle available from several manufacturers insert the 3 5mm phono plug into this connector for power Reticle brightness can be adjusted with the keypad Refer to the section pertaining to reticle illuminator adjustment in the GTO Keypad Manual for further information AUTOGUIDER Connector This connector interfaces with the RJ 11 6 modular jack of an autoguider cable purchased separately or as part of a CCD Imaging Camera or Autoguider The autoguider will be functional and ready to go as soon as you plug it in Please refer to the approp
42. ge of the 1200 mount is approximately 22 69 degrees with considerable overlap at each position Since most astronomers typically observe within one latitude range this adjustment is made just once if at all Prior to shipment we preset the mount to your latitude range for your convenience We suggest that before you travel to an observing location determine the approximate latitude of your observing site and make the appropriate rough adjustment If you live in or plan to travel to locations that are 0 22 degrees latitude we recommend our forthcoming wedge 1200WDG The four positions for the altitude adjustments have the following approximate ranges 57 5 to 69 latitude top position 1 41 to 63 latitude second position 2 30 to 48 5 latitude third position 3 22 to 38 latitude bottom position 4 How to change the position of the altitude adjuster 1 Use only the R A axis DO NOT attempt Polar R A Axis to make these adjustments with the n Altitude Adjustment declination axis in place and certainly not E j Slot with an instrument fully mounted Altitude Locking 2 Loosen both altitude locking knobs about Aide Arbona 1 turn Position Holes 4 h side 3 Locate the side of the polar axis that anana does not have the motor gearbox Tommy Bar housing Loosen about 1 turn the polar i l i Altitude Adjustment axis pivot screw and altitude adjuster bar irab fixing screws on this side only
43. half of the threaded rod protruding from both sides of the altitude adjuster bar This will allow you to move the mount fully within the altitude range will see a small brass altitude adjuster thrust pad This is the part that will come in contact with the polar axis as you ease it back into position Loosen the altitude locking knob i 41 63 motor gear side and lower the polar axis so that it rests 2 comfortably on this pad The threaded rod should be N 2D positioned at roughly a right angle to the polar axis housing lt SHOWN SETTING Firmly tighten the altitude adjuster bar fixing screws Turn the altitude adjustment knob to raise or lower the polar a gt t4 axis to your approximate observing latitude Tighten the altitude locking knobs with finger pressure only You do not need to tighten with the hex key Attach Pier Adapter to Pier Post purchased separately If you purchased the pier from Astro Physics the pier adapter of the 1200 will attach right to the top of the pier If you are constructing your own pier or tripod you will need to incorporate this part Two models of the pier adapter are now available for use with the 1200 from Astro Physics For customers in tropical or extreme polar latitudes a third adapter the Hi Lo Latitude Wedge is in the design stage as of May 2006 and will be available late in 2006 If you have more than one pier you may wish to purchase two adapters so that you can leave them at
44. itial adjustment phase the 4 lock down knobs should be hand tight only This will allow easy movement of the azimuth axis 4 When you are close to the final position of the azimuth axis use a hex key to lock down the rear knob only The azimuth can still be moved with the adjusters but it will now be solidly connected to the pier top The other knobs should remain hand tight The weight of the mount and scope puts pressure on the front of the plate for a solid connection so it is not necessary to lock them down fully with a hex key Altitude Adjustment Loosen the altitude locking knobs Move the polar axis up or down with the large altitude adjustment knob located in the front of the polar axis assembly The tommy bar can be positioned in any of the threaded holes located in the altitude adjustment knob Use this bar to help you turn the knob Please refer to the illustrations on pages 7 and 8 if you are unsure about these parts It is also possible to make fine altitude adjustments by using the turnbuckle on the north leg of our pier if used One full turn of the altitude knob is approximately 0 5 degrees 30 arc minutes Tips for Adjusting the Altitude The mount s polar axis is held in place between the two side plates It is possible for the mount to shift slightly when the side bolts are fully tightened down after adjustment of the altitude angle To prevent that it is suggested that the initial altitude adjustment be done with these bol
45. ition the mount for balancing Move the R A axis so that the counterweight shaft is pointing down The declination axis assembly will be in the meridian this is the classic photographic pose for a German Equatorial Position the Dec axis so the telescope tube is horizontal and pointing east Tighten the 4 R A axis clutch knobs Loosen the 4 Dec axis clutch knobs about 3 4 to 1 turn so that the telescope moves freely about the declination axis Be careful because if your telescope is significantly out of balance it may swing rapidly in the out of balance direction 18 Loosen the tube mounting rings and slide the tube back and forth for balancing This is best done with the tube in the horizontal position If you are using an Astro Physics or Losmandy dovetail mounting plate loosen the hand knobs on the female dovetail plate and slide the male plate and telescope to the desired position The scope is balanced when it stays put does not move with the clutches loose and movement back and forth about the declination axis has the same feel in both directions Be mindful of eyepieces cameras and other accessories that are yet to be added and compensate accordingly Second Balance the Polar Axis 1 Now tighten the declination axis clutch knobs and position the mount with the telescope horizontal and the declination axis horizontal The counterweight shaft is now horizontal with the center of the counterweights the same height as the mi
46. lance the telescope you intend to use Always use two hands to attach or move them on the shaft 8 Reattach the Safety Stop to the end of the declination shaft This will help to prevent injury if someone accidentally loosens the counterweight knob NOTE Firm tightening of the counterweight knob will not damage the surface of the counterweight l j Declination Axi shaft The pin that tightens against the stainless Lock robe 2 counterweight shaft is constructed of brass Likewise the bronze sleeve that has been press fit into the center of the counterweight will prevent marring of the shaft as you move the counterweight up and down Removing Declination Axis at the End of your Observing Session 1 Remove your telescope counterweights and counterweight shaft 2 Unscrew the lock knobs 5 5 to 7 full turns this is still 5 16 to 3 8 out from the fully tightened position and slide tilt the Dec axis assembly in an upwards direction arrow B 3 For transport storage we recommend fully tightening the lock knobs 13 Attach Mounting Plate purchased separately Several mounting plates also called cradle plates are available for the 1200 mount If you own more than one instrument you may need more than one plate Follow the appropriate directions for the plate s that you have The darkened holes represent those used for the 1200 mount 18 FLAT MOUNTING PLATE FP1800 This plate is 18 long and 7 5 at its widest poi
47. ltage spikes A disconnect relay to remove power from both the 12 volt and ground wire is highly recommended in this situation POWER Indicator Light This LED will remain illuminated when your power source has sufficient output to drive the motors If the voltage falls below 10 5 volts the power light will go out and the motors will stop The keypad will not function properly For mounts shipped after 02 25 00 If the LED turns yellow this means that your motors are overloaded probably due to an unbalanced load on your mount Refer to the troubleshooting section of the manual for the solution Earlier control boxes do not have this feature KEYPAD Connector Attach the 5 pin male connector of the keypad controller and lock in place push in the knurled ring then turn RS 232 Connectors These serial port connections are used to connect your mount to your PC computer You must provide your own straight through non crossing cables with a 9 pin DB9 male connector to interface with the GTO panel We have provided the locking posts to secure the cable firmly If your serial cable does not have a 9 pin connector you can use a gender changer or adapter to convert it If your computer has USB ports use a quality adapter to gain a serial port When you are controlling the position of the mount with a computer program such as DigitalSky Voice Software Bisque s TheSky or Imaginova s Starry Night the microprocessor chip located in
48. mesh not set overly tight One symptom of overly tight worm is a chattering sound as the motors try to slew at 1200x or even as low as 600x You can check to see if the worm turns easily with your finger by removing the motor covers and removing the large spur gear to get access to the worm end Try turning it by hand If it does not easily turn then the motor will also have a difficult time turning it Check in our technical section of the AP web site on how to set the worm mesh In real cold weather well below zero F it might also be a good idea to lubricate each of the spur gears and their sleeve bearings with a light machine oil When warmer weather returns this can be replaced with a light grease Lubriplate 105 which will reduce the wear factor in warm temperatures Third under very extreme temperature conditions below 20F it may be necessary to replace the grease on the worm wheel teeth with a lighter material The mounts use a special formulation of Lubriplate 105 with a damping grease added This combination is ideal for low wear since the damping grease portion allows the grease to stay on the teeth and not get wiped off by the motion of the worm Although this combination works well even at temperatures below zero it does get more viscous in really cold conditions We have tried straight low temperature greases that work to 80F and in each case the worm gears get abraded very quickly Using no grease at all is also not recommended for a Go
49. n use the four 4 countersunk through holes marked A located on the top of the plate You can also drill additional countersunk holes to fit your specific requirements A Countersunk through holes for 4 20 cap screws you can use these four 4 holes to attach the mount to a flat surface These holes are on a 3 75 radius bolt circle B The rest of the mount attaches to these locations with hand knobs C These six 6 5 16 18 threaded holes are spaced every 60 on the circumference D The screw that is installed at this location is used to help center the rest of the mounting during assembly 31 CLUTCH PLUG REPLACEMENT FOR 900 OR 1200 MOUNT Who needs clutch plug replacements If the clutch knobs of your 900 or 1200 mount are tightened down with excessive force the plugs under the knobs may deform and splay out This will cause your mount to feel very stiff and you will be unable to back off the pressure of the clutch knobs Once this happens the clutch plugs need to be replaced We have developed a tool part M0100 that will successfully remove the clutch plugs so that you can install new ones If you prefer to make your own tool we offer instructions in the Technical Support section of our website The part number of the clutch plugs is M12665 A Please do not try to substitute your own clutch plugs since incorrect dimensions or composition of the material can impair the performance of your mount What you will find in this
50. necessary re tighten any easily accessible fasteners Additional maintenance information can be found below in the troubleshooting section and in the Technical Support Section of our website ADDITIONAL TIPS AND SUPPORT For additional information regarding the 1200GTO refer to the Technical Support Section of our website We also encourage you to participate in the ap gto user group The members of this group are very knowledgeable about the operation of their mounts CCD imaging and other related issues The staff of Astro Physics also participates and you will find a wealth of information in the archives To find the group link from User Groups in our website s sidebar We encourage you to submit your technical support questions directly to Astro Physics by phone or e mail support astro physics com 26 TROUBLESHOOTING Additional troubleshooting questions are in the GTO Keypad manual Some of the issues discussed in the keypad manual relate to mount communication issues whether you use the keypad or control the mount with a planetarium program or PulseGuide Please refer to them The Declination or R A axis is fairly tight even with the clutch knobs fully loosened This occurs when the clutch plugs have been damaged from over tightened clutch knobs Please refer to the appendix at the end of this manual for detailed instructions on clutch plug removal and how to fabricate your own clutch plug tool The LED on the GTO Control Box
51. nson and Alan Dyer Firefly Books Ltd Rev Ed Oct 2002 ISBN 155209507X The authors both former editors of Astronomy magazine offer practical insight into astronomical equipment finding your way around the sky polar alignment using setting circles and astrophotography This book provides excellent explanations and is well organized and illustrated All About Telescopes Sam Brown Edmund Scientific Company 1975 Sky Pub Corp 5th edition June 1981 ISBN 0933346204 Excellent information regarding the principles of mount construction and operation using setting circles eyepiece projection etc Illustrations and formulas galore Many of the instruments pictured are outdated however the underlying principles are timeless Norton s 2000 0 Star Atlas and Reference Handbook edited by lan Ridpath Addison Wesley Publishing Company 18th edition October 1989 ISBN 058203163X Star maps information regarding polar alignment of German Equatorial and observing techniques 30 STANDARD PIER ADAPTER OF THE 1200 MOUNT Top View _I 1 to 125 6 The 1200 series mount is designed to fit into our 10 outside diameter pier which is available in several heights The pier adapter of the 1200 mount shown above fits into the post aluminum tube of the pier assembly and is secured with six 6 5 16 18 screws at the location marked C If you want to make your own pier you can either use these six 6 side holes marked C or you ca
52. nt in the center The width of the plate tapers to 5 5 at each end Four pairs of keyhole slots that measure 3 2 between centers are provided The two inner pairs are 13 75 apart and the outer two pairs are 17 apart You can drill additional holes to suit your needs This plate also fits the 900 German Equatorial Attach this plate with six 1 4 20 x 1 flat head socket cap screws ene 15 RIBBED MOUNTING PLATE 1200RP15 This plate is 14 75 long 7 75 at its widest point 5 at each end and 1 thick The underside of the plate is carved into a ribbed pattern to maximize the strength and minimize the weight 3 lbs A pair of keyhole slots that measure 3 2 between centers are provided at each end The distance between the pairs is 13 75 Attach this plate with six 1 4 20 x 3 4 socket head cap screws Note that the plate is asymmetrical In most cases orient the plate so that the long end points toward the sky You can also turn the plate in the other direction to balance your scope 24 RIBBED MOUNTING PLATE 1200RP For larger instruments the ribbed structure of this plate provides the maximum support Our machinist begins with thick aluminum plate and carves a strong rib structure The final result is 1 5 thick 24 long and 7 6 at its widest point The width of the plate tapers to 5 5 at each end A pair of keyhole slots that measure 3 2 between centers are provided at each end The distance between the
53. ntenance tasks and your 1200GTO will give you many years of trouble free service Care Although we build it to be rugged enough for field use your 1200GTO is a precision instrument with very accurate worm and wheel adjustments Please be careful if you place the mount on a flat surface i e the ground or trunk of your car The gear alignment may be affected if the R A and Dec motor gear box assemblies sustain undue lateral force This is true of any fine instrument We suggest that you transport and store the mount in a case or in a well padded box ALWAYS disassemble the mount before moving it or transporting it More damage can be done in a few careless seconds in transit than in many hours of normal operation Try to keep your mount protected from dust and moisture when not in use In warm humid weather be aware of the dew that may have formed on the mount while in the field and allow the mount to dry out before packing it away for storage once you get home On the other hand if it is cold and dry outside keep the mount packed up when you bring it into the house until it reaches room temperature to avoid fogging it up The same advice applies to telescopes eyepieces and other equipment in your Astro arsenal Cleaning and Touch up Wipe your mount clean with a soft dry cloth If needed you can use a damp cloth or a cloth that has been sprayed with a mild non abrasive cleaner window or all purpose cleaner no bleach Do not s
54. o hole A of the At the end of the threaded rod mentioned in the last step you Firmly tighten both polar axis pivot screws with the hex key adjuster bar but do not tighten Rotate the altitude adjuster bar around this pivot point until the corresponding hole lines up Consult the diagram to determine which hole of the altitude adjuster bar should be used Be very careful since the holes Polar R A Axis Housing marked C and D are very close to one Altitude Adjuster Bar Do Altitude Adjuster Bar another The incorrect hole may appear to Fixing Screws Don ai Fixing Screws line up however it will be slightly off If you NJ try to attach at the incorrect hole you may i a ea Tommy Bar Strip the threads of the altitude bar The P den Azimuth Adjustment Block correct hole will orient the adjuster to be l l N E Pany hidden Altitude Adjustment roughly perpendicular to the axis once the Kaob axis is lowered into place Once you have located the correct hole Shown with Optional a insert the remaining two screws and lightly Pier Adapter a el tighten so that you still have some ability to North Pier Knob Removed ee B Azimuth Adjustment for clarity Knobs wiggle the bar Note that the altitude adjustment knob is attached to a threaded rod that travels through the altitude adjuster bar Turn the knob so that the altitude adjuster bar is positioned approximately in the middle of the threaded rod You should see about
55. om the clutch hole You may need to use considerable turning force at first to get the old plug to start to unscrew itself About 25 or so revolutions of the screwdriver will be needed to withdraw the plug completely Place a new clutch plug down the hole Place 2 3 drops of light machine oil down the hole Replace clutch knob Repeat above steps with the remaining seven old clutch knobs Updated 08 08 05 32 Construct Your Own Clutch Plug Extraction Tool 055 ET v 2 TU Knife blade edge l on both sides 065 J DBB 0 4 F 150 ak i a 340 190 rkl o j From original rye screwdriver grind a Y L P q E In use the tape should G 3 16 gt lt a Nominal Who needs this tool Clutch Plug Extraction Tool For 900 and 1200 Mounts Tip Details SCALE 2 1 Dimensions 0025 inch Date 8 4 05 Drawn by H K H Data by W A R Tne tool is made from grinding the tip of standard 3 16 inch flat head screw driver of 4 6 inch length 33 If the clutch knobs of your 900 or 1200 mount are tightened down with excessive force the plugs under the knobs may deform and splay out This will cause your mount to feel very stiff and you will be unable to back off the pressure of the clutch knobs Once this happens the clutch plugs need to be replaced solution We have developed a tool that will successfully remove the clutch plugs so that you can install new ones We offer this diagram for
56. ou were to take a long exposure photograph with Polaris often called the north star in the center of the field you would discover that all stars seem to revolve around Polaris This effect is due to the rotation of the earth on its axis Motor driven equatorial mounts were designed to compensate for the earth s rotation by moving the telescope at the same rate and opposite to the earth s rotation When the polar axis of the telescope is pointed at the celestial pole polar aligned as shown in the diagram at right the mount will follow track the motions of the sun moon planets and stars As a result the object that you are observing will appear motionless as you observe through the eyepiece or take astrophotos ASSEMBLY DIAGRAM Please read all instructions before attempting to set up your 1200 mount The Model 1200 is very rugged however like any precision instrument it can be damaged by improper use and handling Please refer to the diagram below for an illustration of the mount The parts are labeled so that we can establish common terminology The following terms and abbreviations are used interchangeably in these instructions polar axis right ascension axis R A axis R A housing declination axis dec axis dec housing Your 1200GTO must be used with a pier adapter which includes the azimuth adjuster block center pivot screw and pier adapter knobs Please choose one as shown below Dec Motor gearbox housin
57. own in photo for the setscrews This will allow you to remove and install your GTO control box without tools GTO KEYPAD OPERATION Please refer to the manual for the GTO Keypad Controller for complete instructions PULSEGUIDE BY SIRIUS IMAGING PulseGuide is a stand alone Windows 98 ME 2000 NT4 XP utility that provides complete remote control of all Astro Physics GTO mounts It derives its name from its most distinctive feature pulse guiding which can improve unguided tracking Specifically it can help correct tracking errors caused by polar misalignment and atmospheric refraction You can also train PulseGuide to track objects moving relative to the stars such as asteroids comets and the moon In addition to pulse guiding PulseGuide also has many useful utility features PulseGuide was written by Ray Gralak of Sirius Imaging The complete PulseGuide user s manual is included on your PulseGuide CD in PDF format Please read it carefully to take full advantage of this powerful mount control software See www pulsequide com for the latest information PEMPROAP BY SIRIUS IMAGING PEMPro Periodic Error Management Professional is a Windows software application that makes it easy to characterize and reduce periodic error PEMPro will analyze the performance of any mount that is equipped with a CCD camera and compatible camera control software PEMPro gives you powerful tools to program your mount s periodic er
58. pe PASILL4 is installed you may remove it to complete these steps Alternatively you can simply sight up the side of the polar axis to see Polaris If you examine the polar axis assembly you will see that the center of the R A shaft is hollow If you have the Standard Pier Adapter or the Hi Lo Latitude Wedge Pier Adapter and have not done so already slightly loosen 1 2 turn the four pier knobs If you have the Precision Adjust Rotating Pier Adapter you do NOT loosen the Pier Knobs NOTE If you have already attached the Dec axis remove the sight hole cover and rotate the internal Dec shaft by moving the top of the Dec axis or the cradle plate if it is attached to reveal the sight hole that has been drilled into it Now you can look through the shaft to the other side Azimuth adjustments To begin with move or turn the entire pier or tripod east or west until the mount is oriented approximately towards the pole an imaginary line drawn through the hollow shaft Use the two fine azimuth adjustment knobs one on each side of the mount to make adjustments You must back off the opposing azimuth knob in order to move the other knob in that direction Please refer to the photos below These photos also illustrate the 14 degrees of azimuth adjustment possible with this mount One full turn of the azimuth knob is approximately 0 53 degrees 31 8 arc minutes Small graduations are 1 06 arc minutes long graduations are 5 3 arc minutes
59. place as much as possible when we disassemble our equipment The setup for the next session is much quicker 24 SLEWING YOUR MOUNT IN BELOW FREEZING TEMPERATURES Notes from Roland during a very cold spell in January 2005 There are several potential problems when slewing your mount in below freezing temperatures The symptoms are a wavering or chattering sound from the motors a slowing down of the slewing with a sudden Jjolting stop at the end of the slew and in the worst case a continuous running of the motors and loss of control have seen similar things on my own mounts when the temperature dips below zero F There are three things that you can look at to alleviate the problem First in cold weather it takes a very much larger amount of power to slew the motors than it does in the summer see tests ran below This extra current drain can cause a voltage drop in the power cord running from the supply to the servo If you have a long distance between the supply and servo use a heavy wire to minimize the voltage drop If the power drops below about 11 volts at the servo terminal the internal computer chips may reset with subsequent loss of control of the motors If your supply is marginal it may also not produce the voltage necessary for proper operation during slews It is a good idea to limit the slew speed to 600x during real cold weather to reduce the power demand from the supply Second it is very important to have the worm
60. pray cleaners directly onto your mount If you use a Cleaning product follow with a damp cloth to remove the chemicals from the mount The painted surfaces of your mount may end up with scuff marks from repeated transport and assembly disassembly Most of the time these marks can be removed with a product like Color Back by Turtlewax automotive product Simply apply with a paper towel and buff out the mark If your paint becomes chipped touch up kits are available for purchase please call us NOTE Paint touch up kits can only be sold to U S customers because of regulations governing shipment of hazardous materials Routine Mount Maintenance Under normal operating conditions minimal maintenance is required Every 12 months the clutch knobs 4 for Dec and 4 for R A should be removed and 1 small drop of light oil 3 in 1 household oil should be put in the exposed hole If the R A and Dec axes are attached together for a long time in outside conditions i e in a permanent observatory then the mating surfaces should be lightly oiled or greased if you expect to get them apart again after 10 years Jostling and vibrations associated with transport to and from observing sites has had the effect of causing screws and fasteners to work their way loose over time We have worked very hard in both the design and assembly of our mounts to alleviate this problem but it is still a good idea to periodically once or twice a year inspect and if
61. riate manual from the manufacturer for operation of the autoguider 21 We offer cables for all SBIG cameras Please refer to our price list or call for further information 6V Connector This 6 volt output accepts 3 5mm phono plugs It is used primarily to power the Pentax 6x7 camera directly from the mount with a cord sold for that purpose our part CORD01 It will supply up to 200mA of current N and S Switch Select northern N or southern S hemisphere as needed When you slide the switch to the opposite position the tracking direction of the drive will reverse The power cord must be removed and re attached to make this work Drainage Holes Two holes are drilled into the lower portion of the bottom of the control box These holes allow excess moisture to drain from your control box particularly useful on dewy nights Please do not plug these holes Removing the GTO Control Box From 1200 Mount The GTO control box can be removed easily from the RA axis It is secured by two 8 32 set screws located at the base of the GTO Servo Control Box Loosen the screws with one of the hex keys from the set included with the mount Lift the box up from the bottom and tilt so that it frees from the dovetail connection Some people have a permanent observatory yet prefer to store their electronics in their home to keep them clean and free of cobwebs If you do you may wish to substitute the 8 32 thumbscrews included with your mount and sh
62. ror correction firmware to achieve the best possible performance for your mount PEMPro dramatically improves guided and unguided imaging resulting in better images and fewer lost exposures PEMProAP is a special version that can only be used with Astro Physics mounts While the periodic error of your 1200GTO will be 5 arc seconds or less you can reduce it even further to maximize performance without auto guiding Please refer to the instructions in PDF format contained on the PEMProAP CD 22 CABLE MANAGEMENT The movement of the mount across the meridian during slewing functions is calculated so that the cables will not tangle if they are set up properly In addition to the motor and power cables that are provided with the mount you may have additional cables for other accessories These may be powered from the GTO Control Panel or from another power source We suggest that you position your cabling carefully to avoid a tangled mess When your cables are set up move the telescope manually throughout the normal range of movement to be sure that the cables do not catch on anything and that you have enough length Here are a few pointers 1200 Motor Cables Note that the Y cable for the 1200 mount originates at the GTO Control Panel connector and then splits into two The short portion connects to the RA motor box and is not likely to be in the way because this axis remains in the same position We have provided a cable mount to po
63. se pairs of holes is 23 Due to the ribbed structure you may not be able to drill additional holes for non Astro Physics mounting rings The plate weighs an amazing 9 5 Ibs for its size This is a view of the rib structure on the underside of the 24 plate Attach this plate with six 1 4 20 x1 socket head cap screws 8 5 DOVETAIL FOR LOSMANDY D SERIES PLATE DOVELM2 This Astro Physics plate attaches to the 400 600E 900 and 1200 mounts If you already own one of the Losmandy DAP series fits Astro Physics refractors DC series for Celestron 8 9 25 or 11 SCTs or DM series for Meade 8 and 10 SCTs plates you should consider this plate or the longer DOVELM16 For larger size SCT s we recommend the longer DOVELM16 see below Note that the bolt hole pattern is offset from the center This allows you to position the plate either forward or backward depending on the balance point of your telescope Attach this plate with four 1 4 20 x 3 4 socket head cap screws and two 1 4 20x5 8 flat head socket cap screws 16 DOVETAIL FOR 1200 MOUNTS AND LOSMANDY D SERIES PLATES DOVELM16 This Astro Physics plate attaches to the 1200 mount If you already own one of the 17 25 or longer Losmandy DAP series fits 6 and larger Astro Physics refractors DC series for Celestron 11 or 14 SCTs or DM series for Meade 10 12 and 14 SCTs plates this is the mounting plate for you Note that the bolt hole pattern is offset from
64. servo motors 0 4 amps at the sidereal rate 3 amps both motors slewing 12 VDC range 11 5 to 16V higher voltage recommended for very cold temps and heavy loads but DO NOT exceed 18V Equatorial head Dec axis R A axis Counterweight shaft 81 Ibs 36 7 kg 31 Ibs 14 1 kg 50 Ibs 22 7 kg 14 lbs 6 4 kg Approximately 140 Ib 63 6kg scope and accessories not including counterweights depending on length Will accommodate Astro Physics and similar refractors up to 206mm f8 16 Cassegrains and Ritchey Chretiens These are only guidelines Some telescopes are very long for their weight or heavy for their size and will require a larger mount INTRODUCTION The 1200 German equatorial was designed to meet the needs of the advanced observer who requires a mount with maximum strength and rigidity and minimum weight The excess material in both axes has been carved out while retaining a heavily ribbed structure for internal strength and rigidity A unique dovetail was machined into the mating surfaces of the R A and Dec axes This feature allows quick and easy assembly in the field without any tools The DC servo motor drive with GTO computer system the keypad with its digital display screen and the included PulseGuide and PEMProAP software all combine to offer extraordinary sophistication for today s observer Whether you enjoy visual astronomy exclusively or plan an aggressive astrophotography or CCD imaging program
65. simply dial in an appropriate amount of RA backlash into the keypad in order to compensate for this RA backlash compensation simply kicks the motor momentarily in the opposite direction at high speed until the opposite teeth have made contact and sidereal tracking can take place The ideal solution is to adjust the worm backlash so that this delay does not occur Please refer to the detailed information in the technical support section of our website lam experiencing trailed stars after a slew and apparently a high variable backlash Check to make sure that the spur gear that is attached to the end of the worm is not loose A loose screw will indeed cause the axis to delay during reversal In a few cases we have seen the set screw on this spur has backed off and needs to be retightened If you have any doubts about where this worm and spur gear is in the scheme of things call Astro Physics and we will talk you through the procedure to check this Remember this Any backlash or looseness in Dec will NOT cause trailed stars after a slew That is because the DEC axis does not move once it gets to its new position so no trailing is possible So if you are getting trailed stars for a short time don t look for something in the Dec axis However the RA axis WILL cause trailed stars after a slew if the spur gear is loose That is because this axis must move at the sidereal rate immediately after getting to the new position If the spur gear is loose on the
66. sition the Dec cable neatly The longer Dec portion of the cable must be set up properly to ensure that as the Dec axis moves the cable follows smoothly Please insert this cable into the cable mount in the upper left corner of the GTO Servo Control Box as shown above When the connector is attached to the Dec motor box the cable should be positioned as shown in the photograph Accessory Cables Accessories may include Kendrick Dew Removers CCD cameras and autoguiders focus motors illuminated guiding eyepiece reticles power cords for the Pentax 6x7 camera etc As you attach each accessory carefully assess the best position to assure complete movement as your telescope slews from one side of the mount to the other If an external power source is used determine the optimum location for the battery We prefer to use tie wraps not glamorous but effective or cable ties from electronic supply store or catalog to secure our cables to the mount telescope rings or bind them together Adhesive cable mounts similar to the one that we use for the Dec cable are an alternative choice We prefer to use ties since we cannot bear to attach adhesive cable mounts to our telescopes or mounts Example from International Space Station Amateur Telescope ISS AT Project If we use tie wraps to secure several cables together and plan to use that same setup in our next observing session we keep the ties in place when we disassemble our equipment The setup
67. sy to characterize and reduce periodic error PEMPro will analyze the performance of any mount that is equipped with a CCD camera and compatible camera control software PEMPro gives you powerful tools to program your mount s periodic error correction firmware to achieve the best possible performance for your mount PEMPro dramatically improves guided and unguided imaging resulting in better images and fewer lost exposures PEMProAP is a special version that can only be used with Astro Physics mounts While the periodic error of your 1200GTO will be 5 arc seconds or less you can reduce it even further to maximize performance without auto guiding PEMProAP is included with all 1200GTO mounts that will ship in 2006 The 1200 is equally at home in a permanent observatory or as a portable mounting for remote star parties thanks to the ease with which the two axes come apart This is the perfect mount for a large refractor Newtonian Cassegrain or astrograph In order to maximize your pleasure on your first night out we recommend that you familiarize yourself with the assembly and basic operation of the mount indoors The temperature will be comfortable the mosquitoes at bay and you ll have enough light to see the illustrations and read the manual Please take particular note of counterbalancing use of the clutches and operation of the keypad controller Why Polar Alignment is Important Compensation for the Earth s rotation If y
68. tached permanently You will probably want to attach the pier adapter to the pier post before going to your observing site We recommend that you leave whichever pier adapter you choose attached to your pier post for transport and storage These pier adapters can be used with all prior versions of the 1200 mount If you did not purchase one of our pier adapters described below for instance if you purchased the Monolith Pier from Particle Wave Technologies you will need to purchase the Pier Adapter Knob Kit part 12KBKIT in order to attach your mount to the Monolith Important notes for all three pier adapters or when using the Monolith Pier Pier Adapter Knob 5 16 IDX 1 OD e The washers for the pier adapter knobs must be positioned with the Stainless Flat Washer smooth surface and rounded edge down so that the assembly can sharp Edge Up be adjusted back and forth Not important for the Precision Adjust 2 Rotating Pier Adapter L oka DOM Polar Fork Bottom Plate e Do NOT remove the center pivot screw Just as the name implies 4 this is the point around which the mount rotates pivots when making azimuth adjustments The screw head has been machined to assure a close fit Please do not replace it with another screw Standard Pier Adapter 1200SPA This 1200 Pier Adapter is similar to those that we have included with mounts in the past however the azimuth adjuster block is slightly taller to accommodate
69. talled with the azimuth block over and between two of the pier post turnbuckles Base Attach the tension rods The turnbuckles should be drawn tight until the whole assembly is stiff enough to support your weight without movement Assemble Polar Axis Assembly to Pier or Tripod In order to track the motion of astronomical objects the polar axis must be positioned so that an imaginary line drawn through the center of the axis points toward the celestial pole Refer to the diagram at the front of this manual for a graphical representation At this stage of the assembly process you want to position the mount so that it points roughly north l 2 Remove the four 4 pier adapter knobs from the Pier Adapter and keep them close at hand Prior to lifting the polar axis assembly into place turn the fine azimuth adjustment knobs so that the space between them is wide enough to allow the pier adapter s azimuth block to fit easily between them Ensure both pier top and polar axis assembly mating surfaces are clean and free of dirt If you are using the Precision Adjust Rotating Pier Adapter make sure that the Altitude Adjuster Block is centered in the slot of the top plate Place the polar axis assembly onto the pier top adapter so that the center azimuth block fits between the fine azimuth adjustment knobs The Center Pivot Screw on the Pier Adapter all models will help you center the mount on the adapter Move the
70. the servo drive box will send continual RA and Dec coordinate data via the cable connections to your computer When you use the software to give instruction to slew to a new object the commands RA and Dec coordinates are sent to the mount We provide two serial port connections on the mount so that you can use two software programs simultaneously For instance you can use PulseGuide for advanced mount control while using TheSky as a planetarium program The telescope control functions of TheSky are more limited so using both in a remote application is advantageous Since the mount will update the RA and Dec coordinates simultaneously both programs are continually updated with the data from the mount You can watch the screen display of 7heSky to see where your telescope is pointing as it slews This is most effective if you have a reasonably fast computer with plenty of RAM If you try this with a 100MHz processor and only 32 MB of RAM the response time will be slow since both programs must be continuously updated with position data You must have two serial ports available on your computer to take advantage of this feature If you use a laptop or a newer desktop computer you may need to purchase a PCMCIA adapter to gain an additional serial port Socket Communications offers adapters for many computers Check out their web site at www socketcom com It is also possible and much cheaper to simply use one or more USB to serial converters dependin
71. those people who wish to make their own tool We also offer the tool for sale as part M0100 Please call Astro Physics for pricing Call Astro Physics to order the clutch plugs part M12665 A Please do not try to substitute your own clutch plugs since incorrect dimensions or composition of the material can impair the performance of your mount Instructions will be provided with the new clutch plugs and are also available from the Technical Support section of our website CHARACTERIZING THE DEC AXIS MOTIONS These instructions explain how to use Maxim DL software as a tool for characterizing any problems with the Declination axis movements of your mount However Ray Gralak s PulseGuide software offers an easier and more extensive evaluation procedure PulseGuide is available as a free download through our website N Aei Ta gt a Step 1 Acquire a reasonably bright guide star and i begin guiding in RA only turn off Dec guiding note X and Y are switched on the Maxim parameter page as of v3 07 Use a 1 second or faster refresh rate so you can see the motion of the guide star as you begin to move it around Magnify the screen to 1600x and place the cursor in the middle as shown Check to make sure that the mount is guiding adequately in RA and that the guide star is not bouncing around due to poor seeing Best results will be achieved when the RA guiding is 0 5 pixels average in RA Step 2 Put the keypad button rate at
72. ts hand tight and as you approach the final adjustment point tighten the bolts with a hex key after each movement If you move the axis too high and overshoot the angle it is better to loosen the two bolts a bit bring the axis back down a very small amount and progress back up with the bolts hand tight This way you are using the weight of the mount to insure a solid connection to the altitude adjuster During the final adjustment phase screw the Tommy bar into one of the holes in the knob This bar can then be used as fine adjustment tool and is a good indication of the position of the axis 17 Understanding the R A and Dec Clutch Knobs We suggest that you read this before assembling the remainder of your system 1 What do they do The four R A and four Dec clutch knobs depicted in the Assembly Diagram on page 6 have the function of connecting the R A and Dec axes to their respective drive worm wheel gears Their function is progressive from no tension axes free to move as required during correct balancing of the telescope to a completely locked up state How can you find out what they really do As shipped all 1200 mounts have all four R A and Dec clutch knobs firmly hand tightened This will give you a good idea of the maximum tightness clutch action that can be achieved by hand effort alone At this point you must bear in mind that for optimum performance all four clutch knobs on each axis R A or Dec should be
73. ts produced after August 2005 and available as an upgrade for earlier mounts e Tropical or extreme polar latitudes 0 to 22 or 69 to the pole North or South choose the Hi Lo Latitude Wedge Pier Adapter Assembly 1200WDGA e 10 O D pier Astro Physics has several heights and styles to choose from e Counterweights 10 Ib 10SCWT and 18 Ib 18SCWT are available e Portable rechargeable battery pack Several sizes and types are available from a variety of vendors Be sure that your battery pack can supply adequate power for an entire observing session see power requirements under Features and Specifications on next page We recommend having separate batteries one for the mount one for all other accessories camera dew remover etc e Regulated Power Supply 110V AC to 12V DC converter two choices 13 8 volt 5 amp supply PS138V5A or 15 volt 10 amp supply PS15V10A Many of these items will be discussed throughout these instructions Several additional options are available e 9 counterweight shaft extension M12675 e Santa Barbara Instrument Group CCD Imaging cameras and ST 4 Autoguider or STV if you plan to pursue CCD imaging or astrophotography e Pier accessory trays for 10 pier TRAY10 and support bars TRAYSB handy to keep your eyepieces close at hand e Polar axis telescope PASILL4 Prior versions sold by Astro Physics will also work threads into the base of the pol
74. u fasten from the side with the six screws and washers provided with the Standard Pier Adapter The bolt circle for attaching the 900 Flat Surface Adapter to your pier is 7 230 diameter Using an ATS pier The O D of the plate will need to be modified by ATS for an additional charge Precision Adjust Rotating Pier Adapter with Azimuth Bearing 1200RPA This pier adapter was designed for very accurate and smooth adjustment of the azimuth angle without loosening the lock down knobs on the base of the mount The top plate of the adapter rotates through the 1200GTO mounts full 14 degrees of azimuth motion It does not rotate through a full 360 degrees This Precision Adjust Rotating Pier Adapter is the ideal choice for portable setups as it makes azimuth adjustment so easy Upgrade your previous model 1200 mount any version and enjoy the ease of use Do a setup followed by a fine polar alignment at a remote site just once and you will wonder how you ever got along without this pier adapter 1200RPA Precision Adjust Rotating Pier Adapter Center Pivot Screw Pier Adapter Mount Bottom Plate Knobs amp Washers Alignment Screws Tension Adjustment screws 3 16 hex The adapter includes the flat plate assembly four machined aluminum lock knobs with 5 16 ID x 1 5 OD stainless washers a tall version of the azimuth adjuster block center pivot screw and six 5 16 18 x 5 8 button head screws and washers Attach to an Astro

1200GTO (for mounts - Astro

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